Income-Tax Mapping for Turkey 2020

main.py

# build and run with Python >3.6

def build_income_samples():
  sample_income_ranges = []
  sample_incomes = []

  sample_income_ranges.append({
    "start": 3000,
    "step" : 1000,
    "stop" : 32000
  })

  sample_income_ranges.append({
    "start": 32000,
    "step" : 10000,
    "stop" : 200000
  })
 
  for income_range in sample_income_ranges:
    for sample_income in range(income_range["start"], income_range["stop"], income_range["step"]):
      sample_incomes.append(sample_income)
 
  return sample_incomes

def calc_tax(income):
  inf = float("inf")
  sgk_upper_limit = 22072

  sgk_payment = income * 0.14 if income < sgk_upper_limit else sgk_upper_limit * 0.14
  yearly_income = (income - sgk_payment) * 12

  tax_brackets = {
    22000  : 15,
    49000  : 20,
    180000 : 27,
    600000 : 35,
    inf    : 40
  }

  total_sgk = sgk_payment * 12
  total_tax = 0
  last_bracket = 0

  for bracket, rate in tax_brackets.items():
    if yearly_income > bracket:
      total_tax += (bracket - last_bracket) * rate / 100.0
      last_bracket = bracket
    else:
      total_tax += (yearly_income - last_bracket) * rate / 100.0
      break

  return round(total_tax), (total_tax / yearly_income) * 100, round(total_sgk)

sample_incomes = build_income_samples()

for income in sample_incomes:
  avg_tax, avg_tax_rate, total_sgk = calc_tax(income)

  print(f"Montly: {income:6} TL, Yearly: {(12 * income):8} TL, SGK: {total_sgk:5}, Avg Tax: {avg_tax:6} TL, Avg Tax Rate: % {avg_tax_rate:.2f}")